Planet continues to warm to “new normal”

The 23rd annual State of the Climate report finds the earth continues to warm, with a record set last year on sea level rise and significant melting of the Arctic Ocean and Greenland ice sheet. Atmosphereic carbon dioxide levels reached 400 parts per million last May, and averaged 392.6 for 2012, the highest in 800,000 years.

The report is “like an annual check up on planet’s health,” said Kathryn Sullivan, acting administrator of the National Oceanic and Atmospheric Administration, which issued the report Wednesday. The report made no assessment of the causes of the observed changes.

The report was peer-reviewed and compiled over nine months by 354 scientists from around the world in disciplines ranging from atmospheric chemistry to oceanography and glaciology.

Last year’s global average temperature was among the 10 warmest years on record, although scientists on a conference call with reporters stressed that no single indicator is adequate to measure the complexity of the climate. Climate change deniers point to the plateau over the past decade or so in global average temperatures.

Temperatures in the upper ocean, to a depth of 2,300 feet, reached a record, or near-record high, the scientists said. Depths below a mile are also warming as the ocean continues to absorb heat.

Sullivan said the new records can no longer be considered anomalies, but rather a “new normal.”

She said the agency offers coastal cities and towns a tool called Sea Level Rise Viewer to help in planning. The tool shows the effects of sea level rise along all the coasts, including of course San Francisco Bay, Houston, Florida and the Mid-Atlantic.

Surface temperatures in 2012 compared to the 1981-2010 average. NOAA map by Dan Pisut, NOAA Environmental Visualization Lab, based on based on Merged Land and Ocean Surface Temperature data from the National Climatic Data Center.